Fix naming issue with serviceBrand

src/browser/TestUtils.test.ts

@@ -7,7 +7,7 @@ import { IEvent, EventEmitter } from 'common/EventEmitter';
 import { ICharSizeService, IMouseService } from 'browser/services/Services';
 
 export class MockCharSizeService implements ICharSizeService {
-  _serviceBrand: any;
+  serviceBrand: any;
   get hasValidSize(): boolean { return this.width > 0 && this.height > 0; }
   onCharSizeChange: IEvent<void> = new EventEmitter<void>().event;
   constructor(public width: number, public height: number) {}
@@ -15,7 +15,7 @@ export class MockCharSizeService implements ICharSizeService {
 }
 
 export class MockMouseService implements IMouseService {
-  _serviceBrand: any;
+  serviceBrand: any;
   public getCoords(event: {clientX: number, clientY: number}, element: HTMLElement, colCount: number, rowCount: number, isSelection?: boolean): [number, number] | undefined {
     throw new Error('Not implemented');
   }